Is Max Planck law true for all electromagnetic waves?

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Discussion Overview

The discussion revolves around the nature of energy in electromagnetic waves, specifically whether it can only be released in discrete packets, as described by quantum theory. Participants explore the implications of this concept in various contexts, including the operation of radio transmitters and the creation of photons in different scenarios.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that energy in electromagnetic waves is released in discrete packets, referencing the concept of photons and their creation during electron transitions in atoms.
  • Others argue that while photons represent a discrete nature of electromagnetic radiation, the same may not apply to all forms of electromagnetic waves, such as those emitted by radio transmitters.
  • A participant mentions Quantum Electrodynamics (QED) as a framework that explains the quantized nature of electromagnetic fields, but expresses uncertainty about its applicability to the specific scenario of radio transmission.
  • It is noted that photons can be created through various processes, not solely through atomic transitions, including the acceleration of free electrons.
  • One participant seeks clarification on how the discrete nature of light can be reconciled with the operation of a radio transmitter, indicating a need for further exploration of this relationship.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of the concept of discrete energy packets to various types of electromagnetic radiation. There is no consensus on whether the discrete nature of photons applies uniformly across all contexts, particularly in relation to radio transmission.

Contextual Notes

Participants highlight the complexity of the topic, with references to quantum field theory and the role of creation and annihilation operators in explaining photon behavior. There are indications of unresolved questions regarding the relationship between discrete energy packets and the operation of radio transmitters.

wolvekampp
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Is it true that the energy in electromagnetic waves can only be released in "packets" of energy?

Or is this only the case for a system where a standing wave change from one mode to another which results in sending out an electromagnetic wave (photon).

In other words if I ride on my bike and connect my dynamo to an electronic circuit to send out low frequency low energy electromagnetic waves (RF radiation) do I have to ride 1 meter extra to create the discrete energy needed for the packet (E=hf)?

If it isn’t true is a photon a special kind of electromagnetic radiation where properties are directly related with the change in the system which created the photon.
 
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wolvekampp said:
Is it true that the energy in electromagnetic waves can only be released in "packets" of energy?

Yes - that's true.

But the correct explanation is Quantum Electrodynamics - QED for short - not the adhoc hypothesis of Plank or even Einstein.

wolvekampp said:
In other words if I ride on my bike and connect my dynamo to an electronic circuit to send out low frequency low energy electromagnetic waves (RF radiation) do I have to ride 1 meter extra to create the discrete energy needed for the packet (E=hf)?

I have zero idea what you mean.

However QED is a Quantum Field Theory and incorporates relativity from the outset.

Thanks
Bill
 
Last edited:
Bill, thanks for your reply. Sadly I didn't find the answer in QED but I learned something new :). What I mean with the bike story is: There is a discrete nature in the way a photon is created when an electron that is bound to an atom move from a higher energylevel to a lower one. I do not see the discrete nature in a radio transmitter. That is why I ask the question. Is there a way to explain the discrete nature of light (electromagnetic waves can only be released in "packets" of energy) if you look at the operation of a radio transmitter.
 
wolvekampp said:
There is a discrete nature in the way a photon is created when an electron that is bound to an atom move from a higher energylevel to a lower one.
There are many other ways in which a photon may be created. Not all light comes from spectral lines. Any time a free electron is accelerated, it radiates electromagnetic waves.
 
wolvekampp said:
Sadly I didn't find the answer in QED

Scratching my head about that. Quantized fields explain exactly why photons exist eg the creation and annihilation operators.

wolvekampp said:
Is there a way to explain the discrete nature of light (electromagnetic waves can only be released in "packets" of energy) if you look at the operation of a radio transmitter.

Yes - the creation and annihilation operators of the quantisized EM field:
http://en.wikipedia.org/wiki/Quantization_of_the_electromagnetic_field

See the section of Fock states.

Thanks
Bill
 

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